Toshiba Programmable Controller PROSEC T3 - Manual (Page 31)

1. System Configuration
1.9
Examining the power
supply capacity
The maximum output current (5 Vdc) of the power supply module
(PS361/PS332) is 7 A. (5.1V at factory setting)
In the standard type expansion configuration, if the power supply
module of the previous unit can supply 5 Vdc to the following units,
no power supply module for the following expansion units is
necessary.
In this case, however, there may be a voltage drop of the 5 Vdc
power caused by the resistance of the expansion cable. The
minimum limit voltage is 4.75 Vdc. It should also be considered.
Basic unit
Exfsansion cable
resistance
= Ro [Q]
Expansion cable
resistance
= Ri [Q]
Expansion cable
resistance
= R2 [Q]
Internal S Vdc current
consumption
^PU+IF+l/0 {A)=lo[A]
Internal 5 Vdc current
consumption
==IF+l/0 (BHi[A]
internal 5 Vdc current
consumption
=IF+l/0 (C)=l2[A]
Internal 5 Vdc current
consumption
=IF+l/0 (D)=l3lA]
Concerning the above figures, the following conditions (1) and (2)
must be satisfied so that the expansion units N0.1 through 3 can be
mounted in the slots using no power supply of their own.
(1) lo+li+l2+l3<7A
(2) 5.1-RoX(li+l2+l3)-RiX{h+l3)-R2Xl3> 4.75V
If either of the above conditions is not satisfied, a power supply
module is needed for the expansion unit.
If a power supply module is mounted on the expansion unit, the
power supply module will supply 5 Vdc to the own unit and to the
following expansion units, disconnecting 5 Vdc line from the
previous unit (OV line is common).
User's manual - Hardware
23